The present invention relates to a measuring arrangement, in particular, for temperature measurement in an accumulator pack for a hand-held machining tool.
With modern hand-held machining tools, the supply of current often takes place by chargeable accumulator packs, which advantageously make possible network-independent, mobile operation. These types of accumulator packs comprise multiple electrically interconnected cells, which store electrical energy, whereby these cells are intensely heated during discharging during normal operation, as well as during charging, which, in extreme case, can lead to damage to the accumulator pack. Therefore, it is known to measure the temperature of an accumulator pack, in order to prevent this type of thermal overload. In this connection, a temperature sensor, such as, for example, a so-called NTC (Negative Temperature Coefficient), is attached to an individual cell, which previously was freed from its paper insulation, by means of a heat-conducting adhesive band, in order to achieve a good thermal binding. Upon exceeding a specified maximum temperature, then, in the simplest case, the operation or the charging process can be interrupted, in order to prevent overheating.
It is also known to cool the cells of the accumulator pack by means of a cooling body, in order to counteract overheating, whereby the cooling body is thermally connected with the individual cells in the common manner and is made of a material with a large thermal conductivity, in order to allow the heat from energy loss in the cells during the discharge or charging process to be carried away well.